Require builder in lib/shoeboxed.rb.
Add Status#document_type_class.
Return document type class name as camel case String.
Refactor methods that will be shared into XmlRequest class.
Add XmlRequest#authed_xml_as_string helper.
Implement finding receipt.
Add missing fields
Merge pull request #7 from jonmagic/request-receipt-info

Request receipt info.